Not Mary
by rejooc
Summary: Here she was. But of course it wasn't really Mary Morstan. Mary herself hadn't really been Mary Morstan. But Sherlock and John had spent so much time reeling from the loss of a woman who had meant so much to them both that now, meeting a woman who looked so much like her was almost too much to take. But it's not Mary. Even Mary was not Mary. And Rosie should meet her grandmother.
1. Chapter 1

His jacket is wet, so he's been in the rain.

Very wet, so he's been outside for a while. Walking?

Ah yes, his shoes and pants are wet, too. Walking then.

His hair is pushed back, so he's been running his fingers through it. Thinking, then, too. Of course, his drawn expression said as much.

No crumbs or stains on his shirt but it's after lunch time. Either he ate very carefully- how out of character- or he hasn't eaten yet.

He keeps licking his lips, so he's thirsty. Dry mouth? Maybe from the stress of whatever he's thinking about.

And the hands. They were his biggest give away since it was so habitual for him to clench and unclench fists when he was upset or stressed.

But so what could be stressing him out?

Normally Sherlock Holmes didn't bother to figure out what perturbed the goldfish of the world, as his brother would put it. Those who were less intelligent and less rational than the Holmes brothers rarely made any significant impact in their lives. Well at least in Mycroft's life.

Certainly, Sherlock was the emotional of the two and he often spent time considering the lives of those closest to him, such as Molly Hooper, something Lestrade, Mrs. Hudson, The Woman, Rosie, and, most importantly, John Watson. And probably Mycroft and Eurus, too, sometimes.

He had learned that John Watson did not appreciate having deductions made about him, so he simply stopped saying them out loud. He tried to look as if he was not looking at all, but of course he was.

Mary would know what to do. What would Mary do?

 _Talk to him._

How very simple and beautifully straightforward.

"Um…" Foolish. Be confident! "John, is something the matter?" Wrong question. John simply fumed, staring at Sherlock for a moment before returning to his pacing.

 _It's obvious though, isn't it, what happened?_  
 _John, you amaze me. You know what happened?_  
 _Not a clue. It's just you normally say that at this point._

Oh, John. Sherlock was missing something and was quite sure it was something he shouldn't be missing. He suddenly felt like pacing, too, which didn't seem productive, either. He considered the things that normally upset John.

Rosie was asleep in the other room, so it wasn't her. Mrs. Hudson hadn't been up for a while so that probably wasn't it, either. Lestrade hadn't been by for a couple of days. Hmm. Perhaps that was it?

"I've been, ah, looking at the website. I haven't seen any cases come in recently but I'm sure something will turn up."

John snorted, laughing humorlessly and shaking his head.

Damn, not that either then.

"Would you, ah, like some, tea? I'm sure Mrs. Hudson's around here somewhere, I can-"

"Sherlock, just stop it." The detective closed his mouth and swallowed a range of emotions he couldn't identify. "You don't know what's wrong and it's driving you crazy. Don't pretend, please. Please just stop it."

Sherlock was quiet, waiting for some sort of clue as to where this "conversation" was going. He turned his eyes towards the door.

Why did he turn his eyes towards the door? Ah, but of course. A vehicle had pulled up a few moments ago and someone had gotten out, he was waiting for them to come inside. Why would they come here?

Without saying anything, he stood and began cleaning the small disheveled living room of 221B. He was quite sure John had mentioned a guest but couldn't seem to remember who would be coming to visit. Whatever the case, it seemed that this was the most likely cause of anxiety for his friend and so he would do what he could to make it better. But what if he doesn't like this person? Would it not be better to leave a mess and hope they leave?

People are so complicated.

He settled for picking up the dishes around the flat and returning them to the sink, draining a jar of eyeballs and returning the solid contents to the refrigerator. Ah, maybe the pantry would be better.

There wasn't really too much time to decide anything before a knock on the door gave Sherlock pause. He hadn't heard any footsteps.

John was trying desperately to appear calm but his clenching fists seemed like blaring indicators to the detective and he had to remind himself that not everyone was so observant.

 _Need to work on your half of the church, Mary. Looking a bit thin._

 _Ah, orphan's lot. Friends – that's all I have. Lots of friends._

Their guest knocked again and John put a hand out as if he was going to grab the door knob but couldn't quite bring himself to do it. Rosie cried and John glanced up towards where she was sleeping.

Sherlock put a gentle hand on his shoulder and nodded.

The army doctor's eyes softened and Sherlock was glad to see that he had been mad at the situation, not at Sherlock himself. He left to attend Rosie and Sherlock rounded on the door, wrapping his long white fingers around the knob and opening it slowly.

"Hello," he said warmly as the door creaked. His voice froze stiffly in his throat as he met eyes with the blonde woman on the other side who looked so much as if she had belonged there—indeed she had been there many times—but who could not possibly be there at all.

Oh, God, he had missed her.

"You're—"

"Rosamund's mother. And grandmother, it would seem. Where is John Watson?" The familiar voice crackled with warmth and Sherlock closed his eyes to control the tears that had welled there. He cried so much for Mary and here she was. But she wasn't really.

"Hello? Are you listening? Where is John Watson? I'd like to meet my son-in-law, please."


	2. Chapter 2

It wasn't the first time Sherlock had been speechless, but it still was uncomfortable for the famous consulting detective, particularly when the situation was so painfully tense. He had considered resorting to humor but his jokes usually fell short and John didn't look ready for laughter. He had been staring at his mother in law without more than a few words for a very long time, it seemed, and all the while she just sat and played with baby Rosie, perfectly content.

"She said she was—"

"An orphan? Yes, she would wouldn't she?"

Silence.

John looked at Sherlock finally, his face clearly displaying his desperation. Of course, the fact that he turned to Sherlock to smooth an uncomfortable social situation was proof enough that he was desperate.

"Um, excuse me, but ah, why are you here?" Ah, tactful as ever, the great Sherlock Holmes had done it again.

John and his mother-in-law both turned to look at him, one looking amused and the other quite frustrated albeit still desperate. Rosie turned, too, but her expression was less telling, since it also involved copious amounts of baby drool.

"You," she nodded towards John, "married my daughter. She has since past away. But I wanted to meet you, and my granddaughter." She nodded again, as if this story was confirmed. Of course, the resemblance she bore to Mary Watson was so close that it was impossible to doubt the blood relation between them.

"Why did she say she was an orphan?" John asked, quietly. It had been so long since he had talked about Mary and Sherlock knew this wasn't the easiest way for him to do it.

"Well, her father did pass away. Well, he disappeared at least. Arthur," she smiled vaguely, "he was so sweet. But anyway, so she probably didn't know where I was. I've been incognito since he passed away."

"Because of the letters?" Sherlock asked suddenly. John closed his eyes, as if he wished Sherlock would do anything but make deductions right now.

"Yes," the woman said simply, "because of the letters, Mr. Holmes. " She put out one small hand to shake Sherlock's as if she hadn't been sitting on the floor of his living room for the past twenty minutes. "My name is Elizabeth."

"That's Mary's—" John coughed, straining as if his voice was suddenly impossibly difficult to use. "Mary's—" His head drooped and the grief that washed over him was visible.

"That was Mary's middle name. That is, the middle name she adopted."

"Mary," Elizabeth smiled, "She always liked 'Mary'." She observed John Watson for a moment before standing, stepping to his side, and wrapping her arms around him. Sherlock picked Rosie up off the floor and watched the very maternal action. To his surprise, John allowed the touch and hugged the strange woman in response, crying stiffly into her side.

"Your daughter was a beautiful person," he finally sobbed, "she was so—she—"

They sat quietly, Elizabeth holding John, Sherlock holding Rosie, and the memory of Mary Watson holding them all.

"Will you take it, Mr. Holmes?" She asked softly, turning her attention to the curly-haired detective. "Will you take my case?"

He nodded solemnly and put out a hand, into which she placed three soft letters, each inked with the same address but different names. Sherlock glanced at them and quickly identified the names as each of the members of Elizabeth's small family—each was addressed to one of Rosamund, Elizabeth, or Arthur—and he wondered at the strange sloping handwriting, as if the letters had been written in the 1600s or by some royal monarch of a long past dynasty. The letters were old, having been written perhaps a decade or more ago.

"Sit, ma'am," John said finally, pointing to the chair in the middle of the room. "You have to."


	3. Chapter 3

Rosie sat happily in her grandmother's lap and Sherlock couldn't help wondering if she was confused about whether or not this woman who looked so much like her mother actually was her mother. There were distinctions though and she was a smart baby; Sherlock wasn't worried. He observed the woman carefully and she seemed satisfied to allow him that time. John had gone to the kitchen to start a kettle and returned as Sherlock began speaking.

"You were young when you had Mary and Arthur didn't tell you about his past until you were already married. He was older and it made sense that he'd have a past, although it was tragic of course when it caught up to him. You've haven't been in touch with Mary since then but you've been to…Antarctica…and found out about Rosie, John, and Mary's death. These letters arrived around the same time, yes? Except that it wasn't the first time you'd received them. Which is part of why you're here." John scribbled frantically, taking notes with a heavy sigh.

"What's in Antarctica?" John asked, hardly looking up enough to catch Sherlock's smirk.

Elizabeth was more stoic and responded carefully, "I have kept in touch."

"But not with Mary," Sherlock clarified.

"No," she whispered, looking suddenly sad. "Not with Mary." She stared down at the baby girl that was the last piece of her daughter and a crystal tear dripped across her cheek.

Sherlock bowed his head, feeling rather like crying himself. John was already there, and sniffled loudly. "What do you see, Sherlock? Clue us in."

"I'll clue _you_ in, John. Unfortunately, Elizabeth has a similar enough path to Mary's that we can be quite certain she is following just fine." Elizabeth nodded and Sherlock continued. "Considering Mary's lifestyle before becoming 'Mary' and Elizabeth's own… _talents…_ it seems fair to assume that Arthur wasn't the only one without a dangerous past, particularly considering his untimely death. Based on Elizabeth's age now and Mary's at the time of her passing, it seems likely that she was quite young when Mary was born and that an older figure must have introduced them both to that life. So, Arthur was older."

"Talents?" John asked, interrupting Sherlock as he opened his mouth to say more.

The detective glanced at his friend and smiled gently. "Her footsteps were silent, her vehicle was 'borrowed,' and she's kept these letters conspicuously hidden on her person despite a lack of bag."

"Yeah, how did you even know about the letters?" John continued.

Sherlock sighed, preferring to hurry along with more interesting things. "She's arrived on a Monday, the typical start of business weeks, so it couldn't have been anything too pressing or unusual as to spark an immediate response. But it did spark a response, so it must have been suspicious. Her car tells us she's not settled in London for long but her lack of bags tells us she is settled for now. A package would have been too bulky to conceal and a note stabbed to her door would've caused a faster reaction."

"But she could have bags in her car," John pressed. Sherlock turned his body towards him, truly beginning to be frustrated. John never spent so much time questioning him, least of all when there were guests around. Why was this different? John nodded encouragingly but there was no hint of a question or curiosity on his wrinkled features.

 _He wants you to impress her,_ he realized, a voice like Mary's sounding in his head. _It matters what mummy thinks._ Sherlock shook his head to hold onto the thought but get Mary's sweet voice out of his head and spoke slowly.

"No she couldn't. Someone who steals a car doesn't trust others not to do the same. There's nothing incriminating in that vehicle."

John nodded, satisfied, and motioned for Sherlock to go on. A small smile turned up the corner's of Elizabeth's mouth, although whether it was directed at the exchange between John and Sherlock, or at Rosie's soft _coo_ s was unclear.

 _Oh, Johnny boy. I'm not coming back._ Sherlock waved a hand, forcing Mary's voice out of his head.

"Right, where was I?"

"Arthur was older," Elizabeth supplied.

"Right," he continued, crossing his legs the other way and cocking his head, directing his comments towards Elizabeth now. "If you'd been in touch with Mary, you would've come sooner, as soon as it was safe. So either Mary didn't know you were alive, like you've said, or didn't want to. Either way, you had to get your information from somewhere and that source has kept you up to date on Mary's wellbeing and John's existence, as well as our address apparently. But he hasn't kept you too well-informed, or you would've come back sooner. So something's happened and Mycroft has something to do with it."

"Mycroft?" John burst, a near laugh tainting his otherwise harsh tone.

"Really, John, did you want an explanation or not?"

"Right, sorry, go on." He turned his focus back to his notebook and scribbled _Mycroft_ at the top of the page, continuing the rest of his notes as Sherlock went on, sighing haughtily.

"These letters aren't strange enough to warrant a trip across the continent to seek a detective when you're probably just as capable of most of this as I am. Not by themselves at least," he stood and held one envelope up to the light, peering closely at the handwriting on the front. "They are strange, that much is certain, but more than that they're recognizable. You'd know this writing anywhere. So you either know who sent them or you'd received them before and done something to be rid of the first set. Burned them probably. Something to ensure they were gone for good. That means you also read them before. Since you're here, I don't think you probably know who the writer is, or at least you don't know how he found you again." He extended an arm towards John, gesturing for him to ask his inevitable questions. To both their surprise, though, it was Elizabeth who spoke up first.

"How'd you know I received these a long time ago? Perhaps I just received multiples? Perhaps the writer as an old friend, long lost, and I needed your help with that?" she asked, throwing the questions at him like a parent might quiz their child before a big test.

"Because," he said simply, spreading the letters so they could all see the fronts and sitting down again, "two of the recipients are dead."

John's eyebrows furrowed into his usual confused expression but Elizabeth nodded. She adjusted on her seat and smiled softly at Sherlock. That warm smile was too familiar and Sherlock drew his eyes back to the letters.

"They contained threats last time," she whispered. "These letters aren't meant to be read, they're meant to be a warning."


End file.
